The present invention relates to a coin discriminating apparatus and, particularly, such an apparatus capable of discriminating whether or not coins are acceptable and the denominations of coins with high accuracy by optically detecting the surface patterns of coins.
Conventionally, discrimination of whether or not coins are acceptable, namely, whether coins are genuine or counterfeit and whether or not coins are current coins is conducted by detecting the diameters, materials, thickness and the like of coins. However, a coin discriminating apparatus for discriminating coins by optically detecting coin surface patterns has been recently proposed in order to improve discriminating accuracy.
For example, Japanese Patent Application Laid-Open No. 8-36661 teaches a coin discriminating apparatus which optically detects the surface pattern of a coin using a CCD area sensor and compares the detected pattern with reference patterns, thereby discriminating the denomination of the coin and whether or not the coin is acceptable.
However, when a coin is made of a material having high light reflectivity such as nickel, aluminum or the like, the total amount of light detected by the CCD area sensor becomes large and saturated if a large amount of light is projected onto the coin and, as a result, it becomes difficult to accurately produce the surface pattern of the coin by detecting light reflected from the surface of the coin. On the other hand, when a coin is made of a material having low light reflectivity such as copper, brass or the like, the amount of light reflected from the coin is too small if a small amount of light is projected onto the coin and, it becomes difficult to accurately produce the surface pattern of the coin. Therefore, this coin discriminating apparatus taught by this laid-open patent application is constituted so as to be able to accurately detect the image pattern of the coin irrespective of the material of the coin by controlling the intensity of light emitted from the light emitting elements or controlling the time period during which the CCD area sensor detects light reflected from the coin based on magnetic properties of the coin.
However, even when a coin is made of a material having high light reflectivity such as nickel, aluminum or the like, the amount of light reflected from the coin is small if the coin is damaged and, on the other hand, even when a coin is made of a material having low light reflectivity such as copper, brass or the like, the amount of light reflected from the coin is large if the coin is a newly issued one. Therefore, when the intensity of light or the light receiving time of the CCD area sensor is controlled in the above described manner, in a case where a coin made of a material having high light reflectivity such as nickel, aluminum or the like is damaged, the amount of light is too small to accurately detect the image pattern of the coin and, on the other hand, in a case where a coin made of a material having low light reflectivity such as copper, brass or the like is a newly issued one, the total amount of light detected by the CCD area sensor is large and saturated, whereby it becomes difficult to accurately produce the surface pattern of the coin by detecting light reflected by the surface of the coin.
It is therefore an object of the present invention to provide a coin discriminating apparatus capable for discriminating whether or not coins are acceptable and the denomination of coins with high accuracy by optically detecting the surface patterns of coins.
The above and other objects of the present invention can be accomplished by a coin discriminating apparatus including a light source for emitting light toward one surface of a coin being transported, reflected light sensor means for receiving light emitted from the light source and reflected by the coin, light emitting means disposed downstream of the light source with respect to a transportation direction of the coin for emitting light toward the one surface of the coin being transported, sensor means for photoelectrically receiving light emitted from the light emitting means and reflected by the one surface of the coin and producing image pattern data of the one surface of the coin, reference data storing means for storing reference data of coins of each denomination, first denomination determining means for calculating coin diameter based on the image pattern data of the one surface of the coin produced by the sensor means, comparing the thus calculated diameter of the coin with reference diameter data of coins of each denomination stored in the reference data storing means and tentatively determining the denomination of the coin, denomination discriminating means for reading reference pattern data of coins of the denomination determined by the first denomination determining means from the reference data storing means, comparing the thus read reference pattern data with the image pattern data of the one surface of the coin and finally determining the denomination of the coin, and received light amount control means for controlling an amount of light reflected by the one surface of the coin to be detected by the sensor means in accordance with an amount of light reflected by the coin and detected by the reflected light sensor means.
According to the present invention, the coin discriminating apparatus includes the received light amount control means for controlling the amount of light reflected by the one surface of the coin to be detected by the sensor means in accordance with the amount of light emitted from the light source, reflected by the coin and detected by the reflected light sensor means. Therefore, in the case where the coin is made of a material having high light reflectivity such as nickel, aluminum or the like, when the coin is damaged and the amount of light reflected from the coin is small, the amount of light reflected by the one surface of the coin to be detected by the sensor means can be controlled to become larger. On the other hand, in the case where the coin is made of a material having low light reflectivity such as copper, brass or the like, when the coin is a newly issued one and the amount of light reflected from the coin is large, the amount of light reflected by the one surface of the coin to be detected by the sensor means can be controlled to become smaller. As a consequence, since the reflected light from the coin received by the sensor means can be reliably prevented from becoming too small and the total amount of light detected by the sensor means can be reliably prevented from becoming too large and saturated, it becomes possible to produce pattern data of the surface of a coin and discriminate whether or not the coin is acceptable and the denomination of the coin with high accuracy.
In a preferred aspect of the present invention, the received light amount control means is constituted so as to control the intensity of light emitted from the light emitting means in accordance with the amount of light reflected from the coin and detected by the reflected light sensor means.
According to this preferred aspect of the present invention, since the received light amount control means is constituted so as to control the intensity of light emitted from the light emitting means in accordance with the amount of light reflected from the coin and detected by the reflected light sensor means, in the case where the coin is made of a material having high light reflectivity such as nickel, aluminum or the like, when the coin is damaged and the amount of light reflected from the coin is small, the light emitting means can be controlled by the received light amount control means so that the amount of light reflected by the one surface of the coin to be detected by the sensor means becomes larger and, on the other hand, in the case where the coin is made of a material having low light reflectivity such as copper, brass or the like, when the coin is a newly issued one and the amount of light reflected from the coin is large, the light emitting means can be controlled by the received light amount control means so that the amount of light reflected by the one surface of the coin to be detected by the sensor means becomes smaller. Therefore, since the reflected light from the coin received by the sensor means can be reliably prevented from becoming too small and the total amount of light detected by the sensor means can be reliably prevented from becoming too large and saturated, it becomes possible to produce pattern data of the surface of a coin and discriminate whether or not the coin is acceptable and the denomination of the coin with high accuracy.
In a further preferred aspect of the present invention, the received light amount control means is constituted so as to control the light emitting means in such a manner that the intensity of light emitted therefrom can be controlled to a high level when the amount of light detected by the reflected light sensor means is small and that the intensity of light emitted therefrom can be controlled to a low level when the amount of light detected by the reflected light sensor means is large.
In another preferred aspect of the present invention, the received light amount control means is constituted so as to control a time period during which the sensor means photoelectrically detects light reflected by the one surface of the coin in accordance with the amount of light reflected from the coin and detected by the reflected light sensor means.
According to this preferred aspect of the present invention, since the received light amount control means is constituted so as to control the time period during which the sensor means photoelectrically detects light reflected by the one surface of the coin in accordance with the amount of light reflected from the coin and detected by the reflected light sensor means, in the case where the coin is made of a material having high light reflectivity such as nickel, aluminum or the like, when the coin is damaged and the amount of light reflected from the coin is small, the sensor means can be controlled by the received light amount control means so that it detects a larger amount of light reflected by the one surface of the coin and, on the other hand, in the case where the coin is made of a material having low light reflectivity such as copper, brass or the like, when the coin is newly issued and the amount of light reflected from the coin is large, the sensor means can be controlled by the received light amount control means so that it detects a smaller amount of light reflected by the one surface of the coin. Therefore, since the reflected light from the coin received by the sensor means can be reliably prevented from becoming too small and the total amount of light detected by the sensor means can be reliably prevented from becoming too large and saturated, it becomes possible to produce pattern data of the surface of a coin and discriminate whether or not the coin is acceptable and the denomination of the coin with high accuracy.
In a further preferred aspect of the present invention, the received light amount control means is constituted so as to control the sensor means in such a manner that the time period becomes longer when the amount of light detected by the reflected light sensor means is small and that the time period becomes shorter when the amount of light detected by the reflected light sensor means is large.
In further preferred aspect of the present invention, the coin discriminating apparatus further includes magnetic sensor means for detecting magnetic properties of the coin being transported and the received light amount control means is constituted so as to control an amount of light reflected by the one surface of the coin to be detected by the sensor means in accordance with an amount of light reflected by the coin and detected by the reflected light sensor means and the magnetic properties of the coin detected by the magnetic sensor means.
According to this preferred aspect of the present invention, the coin discriminating apparatus further includes magnetic sensor means for detecting magnetic properties of the coin being transported and the received light amount control means is constituted so as to control the amount of light reflected by the one surface of the coin to be detected by the sensor means in accordance with an amount of light reflected by the coin and detected by the reflected light sensor means and the magnetic properties of the coin detected by the magnetic sensor means. Therefore, it is possible to more finely control the amount of light reflected by the one surface of the coin to be detected by the sensor.
The above and other objects and features of the present invention will become apparent from the following description made with reference to the accompanying drawings.